Turbine-blade lashing



Feb. 22, 1927. 1,618,292-

H. A. MEIVSSNER TURBINE BLADE LASHING Filed July 30. 1925 HAMeissner\INVENTOR ATTORNEY Patented Feb. 22, 1927.

UNITED STATES PATENT OFFICE.

HERMAN A. MEISSNER, OF ST. PETERSBURG, FLORIDA, ASSIGNOR'TO WESTINGHOUSEELECTRIC &'MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TURBINE-BLADE LASHING.

Application filed July 30, 1925.

My invention relates to elastic fluid turbines, more particularly to theblading thereof, and has for its object the provision of lashing meanstherefor which shall be simple of design, easy of manufacture andapplication, and which shall provide a rigid blade structure effectiveto minimize vibration thereof.

Apparatus embodying features of my invention is illustrated inthe-accompanying drawing forming a part of this specification, in whichFig. 1 is a sectional view, in plan, of a segment of four turbine bladeshaving my improved lashing means applied thereto; Fig. 2 is alongitudinal sectional view along the line IIII of Fig. 1; Fig. 3 is alongitudinal sectional view similar to Fig. 2 illustrating a modifiedform of my invention; and Fig. 4' is a view of a blade and lashingmember illustrative of the process of application.

Turbine blade lashings have heretofore been proposed comprising acontinuous lashing member extending through a series of aligned holes inthe blades and distorted adjacent the blade surfaces in order to securethe members in the blades. Difliculties have been encountered with thisform of lashing, however, due to the fact that the lashing wire isinserted in a row, or segment, of blades upon assembly in the turbineand in that position the only engagement possible to obtain with theblade surfaces is that obtainable by squeezing, or otherwise forcing, apart of themet'al of the lashing member so as to overhang the hole inwhich it is inserted. Due to the rounded contour of the blade surface,the overhung portion of the distorted lashing can only have a verylimited contact with the blade and tends to work loose in operation.

Confronted with this difliculty, it has been found necessary tosupplement the distortion of the metal of the lashing member bysoldering or brazing it to the blade inorder to firmly secure itthereto. The latter method, however, has been found in some in stancesto have a deleterious effect upon the physical properties of the bladesdue to the igh melting point of the solder or brazing spelter employed.

Serial "No. 46,967.

The before-mentioned difficulties are overcome, in accordance with myinvention, by choosing a lashing material having a coefficient ofexpansion substantially equal to that of the blade material and cuttingthe lashing material into relatively short pieces. The lashing members,which are preferably round, are" then flattened at one endand insertedinto a hole provided in the blade during the process of manufacture. Theend inserted in the blade is made to extend beyond the blade and is, inturn, flattened and widened adjacent the blade so as to force thedistorted portion thereof into a close engagement with a relativelylarge'surface of the blade and thus bring it into tight en gagementtherewith. Inasmuch as this form of lashing is applied to the blades inthe process of manufacture, the work is readily accessible and may bedone far more effectively than after theblades are mounted in a bladeholding element. The ends of the extended portions of the lashingmembers are arranged to overlap each other in part, upon assembly of theblades, and may thus be joined together at a point remote from theblades by fusion of metal. The heating incident to the joining process,being at a point remote from the blade surface, has no bad effect on thephysical characteristics of the blades. Furthermore, by choosing alashing material having a coefficientof ex: pansion substantially equalto that of the blade material, alternate heating and cooling of theblading in operation does not tend to loosen the lashing in the'blades.

Referring now to the drawings for a better understanding of my inventionI show in Fig. 1" a fragment of a blade holding element 10 having aseries of blades 11- -11. mounted thereon and having my improved lashingapplied thereto. The lashing comprises membershaving two flattened por-V tions 12 and 13 extending forwardly and rearwardly of each blade in arow and a portion 15 extending through the blade. The portions 12 and 18overlap intermediate the blade at 14, between adjacent blades in a row,as may be more clearly seen by reference to Fig. 2. In accordance withthe modification shown in Figs. 1 and 2, the

portions 12 and 13 are made to overlap bc tween adjacent blades byproviding holes 1t3-lt$ for the portion 15 in the blades, inclined tothe transverse axes of the blades.

In applying my improved lashing, a lashing member is cut lroni roundstock and has its end 12 flattened, as shown in Fig. 1-, leaving theother end conforming to the contour of the hole 16 in the blades. Thehole 16 in the blade is made ol such diameter that the lashing memberthe snugly therein. After inserting the lashing menu her in the hole theportion extending through the blade is flattened and crushed to such anextent that it Forms an engagement with a relatively large portion olthe rounded surface of the blades and is thus caused to come into tightengagement; tl'ierewith. This step in the application 01 the lashing.being carried out in the process ot manufacture of individual bladesseparate from the blade carrying element, may be very etl'ectively done,resulting in a more efl'icient attachment of the lashing member to theblade than is possible to obtain with the blades in place in a bladeholding element. Itmay thus be seen that the lashing members are ineilect rivets having elongated heads extending tor- Wardly andrearwardly of the respective blades and flattened in the direction ofmotive fluid flow.

Referring now to Fig. 3 I show a modified form of my invention WlliClldifi'ers from that in F igs. 1 and 2 in that holes lit 1T are providedin the blades 11 normal to the longitudinal axes of the blades. Insertedin the holes 17 are lashing members 18 which are flattened on each sideof the blade adjacent the surface thereof and are left round at the endswith bevelled surfaces 19 and 21, respectively, overlap 'iing each.other. The process of ilattenilmand securing the lashing members 18 inthe blades 11 may he carried out with this modification in the samemanner as illustrated in Fig. l, thus providing a secure attachment ofthe lashing members to the blades. lVith either form of the invention,the overlapping portions of the lashing members may be readily joinedtogether intermediate the blades by soldering, brazing or welding,n'eterably by the latter method. \Vhen thus oined togetlu-n. theresulting structure otl'ers the maximum of resistance to vibration.

From the toregouig it will be apparent: that l have invented an improvedturbine blade lashing easy of, application, simple of ctmstruction andeffective to offer the maxi mum resistance to vibration of the blades,and a minimum retardation to the flow of the elastic medium.

While I have shown my invention in but two forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleoi various other changes and lnmlilicatious, without departing From thespirit thereof, and I. desire, therefore, that: only such limitationsshall be placed thereupon as are imposed by the prior art or arespecifically set forth in the appended claims.

\Vhat I claim is:

1. Lashing means for a row of tairbine blades comprising individualmembers riveted in each oi the blades extending :lior \vardly andrearwardly thereof and joined together intermediate adjacent blades.

2. in a turbine, the con'ibination oi? a blade carrviiig element, arovvof blades mounted thereon having a series of holes provided therein,individual lashing menihers er-ttending through and secured in each otthe holes, and joined together intermediate adjacent: blades.

3.111 a turbine, the combination of a blade carrying element, a row ofblades mounted thereon having a series of holes provided therein.individual lashing members secured in each of the holes by distortionoli metal on each side. ol, a blade and joined together internualiateadjacent blades by fusion of metal.

4.111 a turbine, the combination of a blade carrying element, a row ofblades mounted thereon having a series of holes provided therein,lashing members extending forwardly and rearivardly of each of theblades, riveted in each of the holes and joined to lashing members ofadjacent blades by fusion of metal.

5. In a turbine, the combination of a blade carrying element, a row ofblades mounted thereon having a series of holes provided therein,lashing members riveted in each of the holes and extending forwardly andrear \vardly of each of the blades and formed to overlap portions oi?adjacent members, Which overlapping portions are joined together byfusion of metal.

6. Iln a turbine, the eon'ibination of a blade carrying element, a rowof blades mounted thereon having a series of holes provided therein,lashii'ig members riveted in each of the blades and extending forwardlyand rear 'ard'ly thereof with portions between the. blades flattened inthe direction of motive fluid liow and arranged to overlap each other inpart. which overlap iing portions are joined together by l'usion ofmetal.

7. In a. turbine, a plurality of blades in a row, lashing membersengaging in openings in the blades and secured to the latter, andadjoining ends of the lashing members being joined togetherintermediately oi the spaces between adjacent blades.

8. In a turbine, a plurality of blades in a row, lashing membersengaging in openings in the blades and secured to the lattor, andadjoining ends of the lashing members being joined together by fusion ofi metal intermediately of the spaces between adjacent blades.

9. In a turbine, a row of blades, a lashing member for each blade havingsurfaces cooperating with surfaces of the blade for connecting the tWo,adjoining ends of the lashing members being disposed between the blades,and means for connecting the adjoining ends of the lashing memberstogether. V

In testimony whereof, I have hereunto subscribed my name this 10th dayof July,

HERMAN A. MEISSNER.

